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Recipes: Effects And Refresh

Use these patterns when the screen needs timed updates, notifications, or explicit message flow.

Recipe: button event -> domain message -> Update(...)​

csharp.cs
private sealed record RefreshRequested : Message;

internal sealed class OrdersApp : TesseraApp
{
    private readonly Button _refresh = new() { Text = "Refresh" };

    public OrdersApp()
    {
        _refresh.Activated += (_, _) => Post(new RefreshRequested());
    }

    public override TesseraEffect? Update(Message message)
    {
        return message switch
        {
            RefreshRequested => RefreshOrders(),
            KeyPressed key when key.IsCharacter('q', ModifierKeys.Ctrl) => TesseraEffects.Quit,
            _ => null
        };
    }

    public override Screen Build(ScreenContext context) => Screen.From(_refresh);

    private TesseraEffect? RefreshOrders()
    {
        // Apply state changes here.
        return null;
    }
}

Use this once widget events start changing real domain state.

Recipe: periodic refresh without self-rescheduling noise​

csharp.cs
private sealed record TickMessage : Message;

public override TesseraEffect? Initialize()
    => TesseraEffects.Periodic(TimeSpan.FromSeconds(5), _ => new TickMessage());

public override TesseraEffect? Update(Message message)
{
    return message switch
    {
        TickMessage => RefreshOrders(),
        _ => null
    };
}

TesseraEffects.Periodic(...) is the cleanest public path when the app needs a recurring tick.

Recipe: add a notification feed​

csharp.cs
private readonly Notifications _notifications = new()
{
    Title = "Activity"
};

private TesseraEffect? RefreshOrders()
{
    _notifications.Push("Orders refreshed");
    return null;
}

Use Notifications for the default visible feed. Use NotificationInbox later when the app needs a denser persistent inbox workflow.

Recipe: put the notification feed into a real shell​

csharp.cs
public override Screen Build(ScreenContext context)
{
    return Screen.Build(window =>
    {
        window.Padding(1);
        window.Right(36, _notifications);
        window.Body(body => body.Use(_refresh));
    });
}